Why Your Tire Pressure Light Comes On in Cold Weather

Every autumn, drivers all over Dartmouth see the tire-pressure light pop on during the first cold mornings. Often it's not a leak at all — it's physics. Here's what's happening and when to worry.

Cold air = lower pressure

Air contracts as it cools. As a rule of thumb, tire pressure drops about 1 PSI for every 5°C the temperature falls. So when a warm fall day turns into a frosty morning, your tires can lose enough pressure to trigger the TPMS warning light.

What to do when the light comes on

• Check your tire pressures when the tires are cold (before driving)

• Inflate to the number on the sticker in your driver's door jamb — not the number on the tire

• Recheck after the first few cold snaps of the season

• If the light returns quickly after filling, you may have a slow leak

Why correct pressure matters more in winter

Underinflated tires have less grip, wear faster, and hurt your fuel economy — all worse in winter conditions. Properly inflated winter tires give you the traction they were designed for.

When it's not just the cold

If a tire keeps losing air, there's likely a nail or a leak. Don't keep topping it up and hoping — get it checked. See our tire services for pressure checks and repairs.

TPMS light on? We'll check it fast. Book online or call (902) 999-7277. Royalz Tire & Lube — 923 Main Street, Dartmouth, NS. Open Monday to Saturday, 9 AM–7 PM.